US 12,221,912 B2
Straddled vehicle
Yoh Aramaki, Shizuoka (JP); Hisatoshi Kinoshita, Shizuoka (JP); Nobuyuki Kawashima, Shizuoka (JP); Ryota Nakashima, Shizuoka (JP); Satoshi Shiokawa, Shizuoka (JP); Ryo Tomii, Shizuoka (JP); Yuta Shimizu, Shizuoka (JP); and Haruhiko Fujita, Shizuoka (JP)
Assigned to YAMAHA HATSUDOKI KABUSHIKI KAISHA, Iwata (JP)
Filed by YAMAHA HATSUDOKI KABUSHIKI KAISHA, Iwata (JP)
Filed on Aug. 4, 2023, as Appl. No. 18/365,587.
Application 18/365,587 is a continuation in part of application No. PCT/JP2022/003596, filed on Jan. 31, 2022.
Claims priority of provisional application 63/146,163, filed on Feb. 5, 2021.
Prior Publication US 2024/0044276 A1, Feb. 8, 2024
Int. Cl. F01N 11/00 (2006.01); F01N 3/10 (2006.01); F02D 41/02 (2006.01); F02D 41/14 (2006.01)
CPC F01N 11/007 (2013.01) [F01N 3/101 (2013.01); F02D 41/0235 (2013.01); F02D 41/1454 (2013.01); F01N 2550/02 (2013.01); F01N 2550/24 (2013.01); F01N 2560/025 (2013.01); F01N 2590/04 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A straddled vehicle, comprising:
an engine, which includes a combustion chamber;
a three-way catalyst, which is configured to purify exhaust gas exhausted from the combustion chamber;
an upstream oxygen sensor, which is provided upstream of the three-way catalyst in a flow direction of the exhaust gas, and is configured to detect an oxygen concentration in the exhaust gas,
a downstream oxygen sensor, which is provided downstream of the three-way catalyst in the flow direction of the exhaust gas, and is configured to detect the oxygen concentration in the exhaust gas; and
a controller, which includes:
a processor, and
a non-transitory storage medium containing program instructions, execution of which by the processor causes the controller to
control a fuel amount supplied to the combustion chamber to periodically increase and decrease the fuel amount, based on a signal input as a signal of an upstream oxygen sensor, and
execute a detachment determination process of determining whether the three-way catalyst is detached based on both the signal input as the signal of the upstream oxygen sensor and the signal input as a signal of the downstream oxygen sensor, when the fuel amount is controlled to periodically increase and decrease based on the signal input as the signal of the upstream oxygen sensor, wherein
the controller is configured
to perform first feedback control, thereby controlling the fuel amount to periodically increase and decrease with a first cycle, based on the signal input as the signal of the upstream oxygen sensor, and
to perform second feedback control, thereby controlling the fuel amount to periodically increase and decrease with a second cycle, based on the signal input as the signal of the upstream oxygen sensor,
the second cycle in the second feedback control being longer than the first cycle in the first feedback control, and/or an amplitude of the fuel amount in the second feedback control being larger than the amplitude of the fuel amount in the first feedback control, and
in the detachment determination process, the controller is configured to determine whether the three-way catalyst is detached based on both the signal input as the signal of the upstream oxygen sensor and the signal input as the signal of the downstream oxygen sensor, while the second feedback control is in execution.